Clustering of HI galaxies in HIPASS and ALFALFA

TL;DR

This paper analyzes the clustering properties of HI-selected galaxies from the ALFALFA survey, comparing them with HIPASS results to understand their distribution and bias relative to dark matter.

Contribution

It provides new measurements of galaxy clustering on smaller scales and for lower HI masses, enhancing understanding of galaxy distribution in the local universe.

Findings

ALFALFA galaxies are more anti-biased with respect to dark matter than HIPASS galaxies.

Clustering measurements extend to smaller angular scales and lower HI masses.

Results improve understanding of galaxy-dark matter bias in HI-selected samples.

Abstract

We investigate the clustering of HI-selected galaxies in the ALFALFA survey and compare results with those obtained for HIPASS. Measurements of the angular correlation function and the inferred 3D-clustering are compared with results from direct spatial-correlation measurements. We are able to measure clustering on smaller angular scales and for galaxies with lower HI masses than was previously possible. We calculate the expected clustering of dark matter using the redshift distributions of HIPASS and ALFALFA and show that the ALFALFA sample is somewhat more anti-biased with respect to dark matter than the HIPASS sample.